公开(公告)号：WO0184687A3

公开(公告)日：2002-02-21

申请号：PCT/US0114013

申请日：2001-04-30

Applicant: SCHWEITZER ENGINEERING LAB INC

Inventor： ROBERTS JEFFERY B ,  HOU DAQING ,  ALTUVE-FERRER HECTOR

IPC: H02H3/08 ,  H02H3/40 ,  H02H9/08

CPC classification number: H02H3/081 ,  H02H3/402 ,  H02H9/08

Abstract: A system for detecting ground faults in a compensated electric power distribution network includes the determination of zero sequence voltage (V0) and zero sequence current (I0) on a power line and calculating the zero sequence conductance (G0) therefrom. The oepration of the conductance calculation circuit occurs only under selected power line conditions involving minimum values of zero sequence voltage, zero sequence current and positive sequence voltage, to ensure the accuracy of a fault direction determination. The conductance values are processed on an adaptive basis in which the difference between the most recent conductance value and a conductance value from a selected previous point in time is determined and then compared against threshold values to make forward and reverse fault declarations.

Abstract translation: 用于检测补偿配电网中的接地故障的系统包括确定电源线上的零序电压（V0）和零序电流（I0），并从其计算零序电导（G0）。 电导计算电路的检测仅在包括零序电压，零序电流和正序电压的最小值的选定电源条件下进行，以确保故障方向确定的精度。 电导值在自适应基础上进行处理，其中确定最近电导值与选定的先前时间点之间的电导值之间的差值，然后与阈值进行比较以产生正向和反向故障声明。

公开(公告)号：WO0233426A9

公开(公告)日：2003-12-11

申请号：PCT/US0132261

申请日：2001-10-15

Applicant: SCHWEITZER ENGINEERING LAB INC

Inventor： ROBERTS JEFFREY B ,  BENMOUYAL GABRIEL ,  ALTUVE-FERRER HECTOR ,  FOLKERS RALPH ,  TZIOUVARAS DEMETRIOS

IPC: H02H3/30 ,  G01R29/16

CPC classification number: H02H3/30 ,  H02H3/307

Abstract: In a power line current differential protection system, all three phase current values (IA, IB, and IC) are obtained from both the local end and the remote end of a power transmission line (12). The magnitude of the ratio of the remote current values to the local current values are calculated. Also, the angle difference between the local and the remote current values for each phase are calculated. Comparison elements (40, 42) then compare the ratio and angle values against preselected values which establish a restrain region in the current ratio plane. Current values which result in the ratio being within the region do not result in a tripping signal for the circuit breaker on the power transmission line (12), while current values which result in a ratio outside of the region result in a tripping of the circuit breaker. Similar circuitry is used for negative sequence current quantities, with the negative sequence preselected values being set substantially lower to produce a more sensitive response to possible faults in the line.

Abstract translation: 在电力线电流差动保护系统中，从输电线路（12）的本端和远端获得所有三相电流值（IA，IB和IC）。 计算远程电流值与局部电流值的比值的大小。 此外，计算每个相位的本地和远程电流值之间的角度差。 比较元件（40,42）然后将比值和角度值与在当前比例平面中建立约束区域的预选值进行比较。 导致比率在该区域内的电流值不会导致电力传输线路（12）上的断路器的跳闸信号，而导致该区域之外的比率的电流值导致电路跳闸 断路器。 类似的电路用于负序电流量，其中负序预选值被设定为低得多，以对该线路中的可能故障产生更敏感的响应。